This paper computes the share of all household giving accounted for by the American households donating the largest amounts over the 1960–2012 period. The share of donations accounted for by a minority of top donors has risen sharply over this period. This rising concentration is driven by both larger gifts at the top and reduced giving by the broad majority of households. Charities are increasingly dependent on major donors, and the share of donations flowing to the charities receiving the highest levels of donation revenue has risen. The 2017 Tax Cut and Jobs Act preserved or increased donation incentives for many top donors, and is likely to decrease aggregate charitable giving by less than is widely feared, while accelerating the concentration of giving among those who give the most.